Hired farm workers provide the majority of the workforce for California's labor-intensive agricultural sector, and they also suffer the greatest health burden. California's hired farm workers face increased risks of morbidity and mortality from respiratory disease, musculoskeletal problems, infectious diseases, stress- related mental health disorders and lifestyle-related diseases such as obesity. There has been very little research into the etiology of the poor health outcomes that occur disproportionately in this population. The overall goal of this proposed project is to continue with a longitudinal follow-up of a cohort of hired farm worker families in California that was established through supplemental funding from NIOSH. We propose to conduct two follow-up assessments of the MICASA study cohort in Mendota, California to assess the incidence and prevalence of diseases in this population. These follow-up assessments will be conducted on the 400 families comprising our farm worker cohort in Mendota. Interviews will be conducted with all MICASA study participants (both the head of household and spouse) twice during the five-year study period. We will also conduct pulmonary function testing, measure vital signs and take anthropometric measurements at two time periods in the population. Finally, the exposure assessment component will collect quantitative data on particulate exposure in this population. The specific aims of the study are to: 1) measure the incidence of respiratory symptoms and agricultural injuries and assess the independent association of agricultural exposures and lifestyle factors to respiratory symptoms, agricultural injuries, and musculoskeletal problems; 2) examine the prevalence and determinants of atopy, asthma and asthma symptoms; 3) determine levels of particulate matter exposure for tasks and crops commonly conducted by agricultural workers in our population; 4) examine incident respiratory symptoms and changes in pulmonary function over time and assess the relationship between predictors such as occupational factors with incident symptoms and changes in pulmonary function. This approach allows us to address a wide range of factors affecting health including work, home environment, and personal health behaviors. This cohort is being established to improve understanding of important health risks and to provide a basis for the design of effective public health and clinical interventions, and ultimately to improve the health of this underserved population.